Move tst_qshortcut.cpp to QtWidgets

QShortcut belongs to QtWidgets instead of QtGui.

Change-Id: I9715399bb372a6ea4bd76109f87ba31a1e30a7e6
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

tests/auto/gui/kernel/kernel.pro

@@ -13,7 +13,6 @@ SUBDIRS=\
    qmouseevent_modal \
    qpalette \
    qscreen \
-   qshortcut \
    qtouchevent \
    qwindow \
    qguiapplication \

tests/auto/widgets/kernel/kernel.pro

@@ -14,6 +14,7 @@ SUBDIRS=\
    qwidget_window \
    qwidgetaction \
    qicon \
+   qshortcut \
 
 SUBDIRS -= qsound